Example For Mark on expression tree with mulitple parameters

expressionTreeDemo.linq

void Main()
{
	var l = new FileModel[] { new FileModel() { Filename = "pizza is great" },
		new FileModel {Filename = "MarkyMark"},
		new FileModel {Filename = "JeffyJeff"}
	}.AsQueryable();
	var subStrings = new string[] {"is", "pizza","pizza","pizza","Mark"};
	
	l.MultiValueContainsAny(subStrings, t=>t.Filename).Dump("Filters to");
}

public class FileModel {
	public String Filename { get; set; }
	public long Length { get; set;}
}

// Define other methods and classes here
public static class MyExtensions
{
	public static IQueryable<T> MultiValueContainsAny<T>(this IQueryable<T> source, ICollection<string> searchKeys, Expression<Func<T, string>> fieldSelector)
	{
		if (source == null)
			throw new ArgumentNullException("source");
		if (fieldSelector == null)
			throw new ArgumentNullException("fieldSelector");
		if (searchKeys == null || searchKeys.Count == 0)
			return source;

		MethodInfo containsMethod = typeof(string).GetMethod("Contains", new Type[] { typeof(string) });
		Expression expression = null;
		foreach (var searchKeyPart in searchKeys)
		{
			Tuple<string> tmp = new Tuple<string>(searchKeyPart);
			Expression searchKeyExpression = Expression.Property(Expression.Constant(tmp), tmp.GetType().GetProperty("Item1"));
			Expression callContainsMethod = Expression.Call(fieldSelector.Body, containsMethod, searchKeyExpression);

			if (expression == null)
				expression = callContainsMethod;
			else
				expression = Expression.OrElse(expression, callContainsMethod);
		}
		return source.Where(Expression.Lambda<Func<T, bool>>(expression, fieldSelector.Parameters));
	}
}